The counter argument is that physical also has issues depending on the format as discs do wear out over time while solid state formats also share the same risk of dying like hard drives, providers going out of business or not providing the product anymore hits both digital and physical only with digital depending on the platform the game can remain available for purchase if they go out of business or still be redownloaded if the publisher pulls the game because of consumer rights laws an example are the Crysis games on Steam I can still download them on Steam even though EA pulled them from Steam long ago. With physical if something happens to your copy you could end up having to pay hiked up prices to rebuy the game.
It's true that no hardware lasts forever, but Switch carts and systems are likely to still be functional decades from now if properly treated, so I'm good. In the here and now, besides the fact I like physically owning the games, I'm also saving myself the unneeded extra expense of having to get another SD card or hard drive for my Switch if I were to fill the one I have by buying everything digitally.
I don't know. I'm fully digital aside from my copy of Zelda but I hear lots of physical games are actually only part physical and you have to download the rest.